Server-Sent Events (SSE)

Server-Sent Events (SSE) is a standard for pushing real-time notifications from a server to a Browser over a single HTTP connection. Unlike WebSockets, which provide full-duplex, bidirectional communication, SSE is strictly unidirectional, sending data from the server to the client. This makes it a highly efficient choice for applications like live news feeds, social media updates, and financial tickers where the client does not need to send frequent data back to the server.

The technology is part of the HTML5 specification and utilizes the JavaScript EventSource API to manage the connection. According to the MDN Web Docs, the server must respond with the text/event-stream MIME type and keep the connection alive. A significant advantage of SSE over Long Polling is its native support for automatic reconnection and event identification, as detailed in the WHATWG Living Standard. Because it operates over standard HTTP, it often bypasses firewall restrictions that might block other protocols.

• WebSockets
• Real-Time-Web
• HTTP-Streaming
• Push-Technology